Sulfur-Doped Phosphorene as a Promising Anode for Na and K-Ion Batteries

In the present work, a novel anode candidate – sulfur-doped phosphorene – for the Na-ion batteries and K-ion batteries has been proposed. The doped geometry, Na/K adsorption energy, average open-circuit voltage, specific capacity, Na/K diffusion barriers, and charge transfer on sulfur-doped phosphorene sheets are investigated through the way of adopting ab initio periodic quantum chemical method. The results demonstrate that, toward the directions of armchair and zigzag, the energy barriers of Na/K diffusion on the doped monolayer are 0.81/0.68 and 0.14/0.08 eV, respectively. In addition, the theoretical specific storage capacity of sulfur-doped phosphorene in Na-ion batteries is 431 mAh g⁻¹, which is larger than for other commercial anode materials. Besides, the Na/K insertion/diffusion in sulfur-doped phosphorene well preserves its structural integrity. Owing to its good stability, high capacity, excellent electrical conductivity and high Na/K mobility, sulfur-doped phosphorene will have immense application prospects as anode material for Na-ion batteries, K-ion batteries and other novel electronic devices.